title: Do sex and atopy influence cough outcome measurements in children?
abstract: BACKGROUND
  Despite the commonality of cough and its burden, there are no published data on the relationship between atopy or sex on objectively measured cough frequency or subjective cough scores in children. In 202 children with and without cough, we determined the effect of sex and atopy on validated cough outcome measurements (cough receptor sensitivity [CRS], objective cough counts, and cough scores). We hypothesized that in contrast to adult data, sex does not influence cough outcome measures, and atopy is not a determinant of these cough measurements.
  
  
  METHODS
  We combined data from four previous studies. Atopy (skin prick test), the concentration of capsaicin causing two and five or more coughs (C2 and C5, respectively), objectively measured cough frequency, and cough scores were determined and their relationship explored. The children's (93 girls, 109 boys) mean age was 10.6 years (SD 2.9), and 56% had atopy.
  
  
  RESULTS
  In multivariate analysis, CRS was influenced by age (C2 coefficient, 5.9; P = .034; C5 coefficient, 29.1; P = .0001). Atopy and sex did not significantly influence any of the cough outcomes (cough counts, C2, C5, cough score) in control subjects and children with cough.
  
  
  CONCLUSIONS
  Atopy does not influence important cough outcome measures in children with and without chronic cough. However, age, but not sex, influences CRS in children. Unlike adult data, sex does not affect objective counts or cough score in children with and without chronic cough. Studies on cough in children should be age matched, but matching for atopic status and sex is less important.
authors.affiliation: Queensland Children's Respiratory Centre and Children's Medical Research Institute, Royal Children's Hospital, Brisbane, QLD, Australia; Child Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia. Electronic address: annechang@ausdoctors.net.
authors.forename: Anne B
authors.initials: AB
authors.lastname: Chang
authors.affiliation: Department of Respiratory Medicine, John Hunter Hospital, University of Newcastle, NSW, Australia.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Gibson
authors.affiliation: Queensland Children's Respiratory Centre and Children's Medical Research Institute, Royal Children's Hospital, Brisbane, QLD, Australia.
authors.forename: Carol
authors.initials: C
authors.lastname: Willis
authors.affiliation: Queensland Children's Respiratory Centre and Children's Medical Research Institute, Royal Children's Hospital, Brisbane, QLD, Australia.
authors.forename: Helen L
authors.initials: HL
authors.lastname: Petsky
authors.affiliation: University of London, London, England.
authors.forename: John G
authors.initials: JG
authors.lastname: Widdicombe
authors.affiliation: Queensland Children's Respiratory Centre and Children's Medical Research Institute, Royal Children's Hospital, Brisbane, QLD, Australia.
authors.forename: I Brent
authors.initials: IB
authors.lastname: Masters
authors.affiliation: Department of Respiratory Medicine, Royal Children's Hospital, Melbourne, Murdoch Children's Research Institute, University of Melbourne, VIC, Australia.
authors.forename: Colin F
authors.initials: CF
authors.lastname: Robertson
mesh_terms: D001249:Asthma / Q000150:complications / Q000175:diagnosis; D002211:Capsaicin; D002648:Child; D003371:Cough / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000150:complications* / Q000175:diagnosis; D008297:Male; D012727:Sex Characteristics; D012882:Skin Tests
chemical_list: D002211:Capsaicin